STORY: First, it takes place in another world where it contains an explosion and fleet of monsters are battling against Riku Suigin. There is also a flashback on how Suigin & Rei met one year ago. In the anime, you can also see Suigin working in multiple part-time jobs in order to be enrolled in his school. There is also another side to him where he is playing an online PC game called Dungeon Century during his free time. Things become more interesting once the gaming company announced the game will shut down. It became Suigin's mission to save Rei from her abductors.

Riku Rei: One of the popular girls in school, smart student, her family are part of the God Grave Tech Company and created Dungeon Century & Grave Buster, gamer, kind and has pink hair.
Riku Suigin: Gamer, works in multiple part-time jobs to make ends meet, has a cat named Wanchoi.

OVERALL: This anime is from the same creators that brought you BLOODIVORES. (Japanese anime with Chinese Influences). First episode doesn't explain a lot. The plot can be quite confusing at times too. Personally, I think the first 5 episodes are fillers. It does have its sweet, romantic moments, and action scenes. The episodes are 13 minutes long for this series.